SoftwareSerial magic numbers

Next test - longer string "the quick brown fox jumps over the lazy dog" (42 chars) sent from A-> B at different speeds starting at 100 baud step size 100.
B sends back the number of chars correctly received from start of the string. so when receiving "theXquick brown fox jumps over the lazy dog" the answer would be 3.

Again we see baud rates up to 70K perform 100%, above failing starts...

BAUD 	CHARS
74800	34	 FAIL
79900	11	 FAIL
81000	3	 FAIL
84900	31	 FAIL
85200	23	 FAIL
85800	21	 FAIL
86200	15	 FAIL
86300	20	 FAIL
86600	38	 FAIL
86900	41	 FAIL
87100	38	 FAIL
87300	15	 FAIL
87400	20	 FAIL
87700	38	 FAIL
88300	20	 FAIL
88400	170	 FAIL  <<<< a very strange one ???
88500	37	 FAIL
88700	18	 FAIL
88800	15	 FAIL
89000	38	 FAIL
89200	38	 FAIL
89500	15	 FAIL
89600	12	 FAIL
89800	18	 FAIL
90000	31	 FAIL
..

For the statistics: highest successful transfer rate was 103800 baud,

Conclusion:
Up to 70K the formula based SoftSerial does work as expected, that is about 20% faster than 57600 from the fixed tables.

115200:
As the values are identical to the table based SS for 115200, I do not expect the (exisiting) table version to work at least for receiving data.